We've mentioned this application before, but it has since updated with more features including minimizing applications to the system tray, setting windows always on top, and assigning per-window transparency. Readers using Windows XP will also get extra features—the ability to completely hide a single window, or hide all windows except the current one behind the PMW tray icon—making this low-resource, portable application worth a look for anybody interested in better control over running processes. Process Manager for Windows is free and open source, available for Windows only.